Field of the Invention
The present invention relates to an electrophotographic member which can be used as a charging member or the like to charge the surface of an electrophotographic photosensitive member as a member to be charged to a predetermined electrical potential by applying a voltage, and a process cartridge and an electrophotographic image-forming apparatus (hereinafter, referred to as an “electrophotographic apparatus”) using the same.
Description of the Related Art
An electrophotographic apparatus employing an electrophotographic method primarily includes an electrophotographic photosensitive member (hereinafter, simply referred to as “photosensitive member”), a charging device, an exposing device, a developing device, a transferring device and a fixing device. As the charging device, a contact charging device which charges the surface of a photosensitive member by applying a DC voltage or a voltage of a DC voltage superimposed with an AC voltage to the charging member brought into contact with or closely disposed on the surface of the photosensitive member is commonly employed.
Japanese Patent Application Laid-Open No. 2012-103414 and Japanese Patent No. 4799706 disclose a charging member including an electro-conductive resin layer containing a bowl-shaped resin particle having an opening, wherein the charging member has an uneven shape derived from the opening and edge portion of the bowl-shaped resin particle on the surface. In the charging member described in Japanese Patent Application Laid-Open No. 2012-103414 and Japanese Patent No. 4799706, the edge portion of the opening of the bowl-shaped resin particle on the surface is elastically deformed to relax the contact pressure onto a photosensitive member. As a result, the nonuniform abrasion of a photosensitive member can be suppressed even in a long-term use.
The present inventors have confirmed that the charging member according to Japanese Patent Application Laid-Open No. 2012-103414 and Japanese Patent No. 4799706 can exhibit a stable charging performance and effectively suppress the nonuniform abrasion of a photosensitive member in contact with the charging member. However, the present inventors have recognized that the charging member according to Japanese Patent Application Laid-Open No. 2012-103414 and Japanese Patent No. 4799706 still needs to be improved in the stability of charging performance in response to the recent increase in the speed of electrophotographic image-forming process.